1. Field of the Invention
The present invention relates to an evaporation plate for ice making machines and, more particularly, to an improvement in the evaporation plate for ice making machines, disclosed in Korean Patent Application No. 97-21,415 applied by the inventor of this invention, to form a serpentine evaporation passage in an evaporation plate by integrating two channeled panels into a single plate different from a conventional evaporation plate having a separate serpentine evaporation tube welded to the top surface of the evaporation plate.
2. Description of the Prior Art
In recent years, the terrestrial air temperature has been gradually increased due to global warmth and results in a quick increase in the consumption of ice. Particularly, since some agricultural and marine products, such as vegetables, fishes and shellfishes, are very apt to be spoiled during their circulation, it is necessary to use ice with such products for preventing them from spoiling during the circulation. In addition, ice also has been typically used in hotels, restaurants, etc, for keeping freshness of foods for a necessary period of time and for cooling beverages. It is thus necessary to produce a very large quantity of ice so as to provide ice to such consumers every day.
Such commercial ice has been typically produced using ice making machines. As well known to those skilled in the art, such ice making machines use a refrigeration cycle in the same manner as that of conventional refrigeration systems, such as refrigerators, freezers and air conditioners. In such a conventional refrigeration system, refrigerant flows through a refrigeration cycle while losing or absorbing heat during heat exchanging processes with surrounding air as follows: In such a conventional refrigeration cycle, gas refrigerant output from an evaporation plate acting as an evaporator is compressed at a compressor to become high temperature and high pressure gas refrigerant and is fed to a condenser. The condenser condenses the gas refrigerant to make saturated liquid refrigerant and feeds the refrigerant to a liquid/gas heat exchanger. In the liquid/gas heat exchanger, the saturated liquid refrigerant loses heat through a heat exchanging process with low temperature and low pressure gas refrigerant, thus becoming saturated cold liquid refrigerant. This saturated cold liquid refrigerant is, thereafter, fed to a dry filter.
The above dry filter consists of a refrigerant inlet port, a refrigerant outlet port, and a filter body provided between the two ports while connecting the ports together. An iron net and cotton are set within the body at the front and rear portions of the body. An absorbent is set within the dry filter and removed moisture and impurities from the refrigerant. The cold liquid refrigerant output from the dry filter, thereafter, passes through both a capillary tube and an expansion valve. The liquid refrigerant becomes expanded refrigerant having low temperature and low pressure. The refrigerant is, thereafter, fed into the evaporation plate to absorb heat from water filled in an ice making cell plate positioned around the evaporation plate, thus making desired ice cubes. The refrigerant is, thereafter, returned to the compressor to repeat the above-mentioned refrigeration cycle. The present invention particularly relates to such an evaporation plate acting as an evaporator of the above-mentioned evaporation system.
FIGS. 1a and 1b are perspective views, showing a conventional evaporation plate for ice making machines, with a separate serpentine refrigerant tube welded to the top surface of the evaporation plate into a single structure. As shown in the drawings, the conventional evaporation plate 30 has a separate serpentine evaporation tube 20 welded to the top surface of the plate 30. That is, the evaporation plate 30 comprises a flat panel covering the top of an ice making cell plate 10 having a plurality of cells 5. The separate serpentine evaporation tube 20 is firmly welded to the top surface of the flat panel covering the top of the cell plate 10.
However, such a conventional evaporation plate 30 is problematic in that the separate serpentine evaporation tube 20 is firmly welded to the top surface of the flat panel covering the top of the cell plate 10, and so the evaporation tube 20 spoils the appearance of the evaporation plate 30. In addition, it is very difficult to repeatedly and precisely bend the evaporation tube 20 to form a desired serpentine shape having a plurality of U-shaped portions, thus being reduced in work efficiency and productivity while producing evaporation plates 30. The serpentine evaporation tube 20 may be also weakened in its structural strength at the U-shaped portions and may be thermally weakened at the welded portions, thus sometimes causing undesirable leakage of refrigerant from the tube 20.
The separate serpentine evaporation tube 20, welded to the top wall of the evaporation plate 30 while projecting upward from the top wall, undesirably reduces heat conductivity of the refrigerant and is apt to be easily damaged or broken due to external impact. In addition, since the evaporation tube 20 has to be mounted to the top wall of the evaporation plate 30 through a welding process, it is very difficult to integrate the evaporation tube 20 with the evaporation plate 30 into a desired single structure. Another problem of the conventional evaporation plate 30 resides in that the evaporation tube 20 is regrettably somewhat spaced from the top wall of the evaporation plate 30 even though they are welded together into a single structure. This further reduces heat conductivity of the refrigerant.